Deleting a NodeJs app from server

I have configured a server for NodeJS and ran a Hello World app at the localhost:8080.

I am configuring a server for first time, so i have just tested my server with this app. Now i want to run another app at the localhost:8080. So i have tried to delete previous app, which is running from a hello.js file -

sudo rm -rf hello.js

File is deleted now but the app is still running at localhost:8080. I have tested with